She has emerged from a bubble gum pink 2011 Rolls Royce Ghost looking to the discerning eye like a human Barbie doll, all slim brown skin and bouncy white blonde hair. But as we all know, appearances can be deceiving. Beneath her beautiful exterior is a determined, driven and self-aware businesswoman. Underneath her sweetness lies steel.

At just 23 years old, Petra Stunt nee Ecclestone, the millionaire daughter of Formula One CEO Bernie Ecclestone, is one of the richest women in the world. She purchased the late Aaron Spelling’s Beverly Hills abode, which, at 57,000 square feet, is the largest residence in Los Angeles County, for $85 million last year. Her wedding to entrepreneur James Stunt, also in 2011, reportedly cost $19 million. The bottom line here: Petra does not have to work—but she does, and tirelessly.

“I hate when I wake up and have nothing to do!” she discloses. “I love having a purpose. I love going into the office and being preoccupied on a day-to-day basis. It gives me a meaning to life.”

In 2008 at the very young age of 19, she created the menswear label FORM. When it folded after 14 months of operation, she then bounced back by launching Stark, a luxury handbag line comprised mostly of designer clutches.

However much a passion project it may be, Petra is fully invested in Stark. And though it might surprise some,she is not one to shy away from the less glamorous day-to-day operation of running a company.

“It’s a lot of work, but I love it,” the British heiress declares. She is perched on a couch in the living room of real estate developer Mohamed Hadid’s stunning Beverly Hills mansion, looking prim, proper and very posh. She is so posh, in fact, that we are surprised at the vehemence of her next statement. “I hate when I wake up and have nothing to do!” she discloses. “I love having a purpose. I love going into the office and being preoccupied on a day-to-day basis. It gives me a meaning to life.”

In addition to being Petra’s raison d’être, Stark is also rapidly becoming a huge success. It has only been in existence for two seasons, but is now being sold in 25 stores, including Saks and Intermix, and retails for up to $65,000. Much like Petra herself, the bags are opulent yet understated, created entirely of exotic skins and Swarovski crystals.

In addition to creating something she actually loves to buy herself, Petra knew that her venture would be financially lucrative. For that same reason, she is also a strategic businesswoman, as she knows when to cut her losses and walk away. “I wanted to do accessories because I had a menswear label and realized the product was too expensive to make and there was no real profit margin,” Petra explains while speaking of Form’s demise. She adds, “With accessories, I had an opportunity to make a much larger profit, so I decided to go for it. I’ve loved handbags forever, so it made sense.”

She is especially proud of her latest collection, a series of animal-inspired clutches featuring her company’s panther insignia. “I love each bag having details,” she says. “They’re real showpieces. You don’t have to wear a lot of jewelry or anything flashy when you carry one.”

By definition, “stark” means to be severe or bare in appearance, which is a tongue-in-cheek way for Petra to let the world know that things aren’t always what they seem. “Stark is the complete opposite of the bag. When you think of ‘stark’, you think neutral and white and plain. The bags themselves are detailed and out there.” She adds, “For the first season, I had the model in our ad campaign shot naked, because I wanted to do a play on words: ‘stark naked.’ I wanted to do something sexy with a word that didn’t really mean one thing, but that had hidden meaning.”

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As it happens, Petra could be referring to herself. “I’m really dressed down in the day and I don’t wear heels unless I have to go to a fancy event; I don’t like being uncomfortable. A nice bag makes me feel really special.”

But contrary to popular opinion, the heiress doesn’t abuse her wealth; she is not the sort to shop until she drops at every waking moment. Instead, she invests in classic pieces she’ll own forever.

“I do have an extensive handbag collection,” she admits, adding that her favorite, above all else, is the Hermes Birkin bag. “I love timeless things that you can wear from season to season. I hate seeing a piece and knowing exactly what season it’s from, like a Chloe or a Yves Saint Laurent. To me, the Birkin embodies timelessness. I can pass it on to my children the way my mum passed on her bag to me.”

Sharing accessories is just one of the ways that Petra bonds with her mother, Slavica, and older sister Tamara, both of whom are currently in Los Angeles and staying at the her mega-mansion. “We love to share,” she says, smiling fondly. “I don’t have their same shoe sizes, so my sister, mum and I share our bags.”

Given how she lights up when speaking about her family, it’s understandable that Petra is happy to have her nearest and dearest close by. She is equally as enthusiastic when talking about her love for Los Angeles, but admits that making the transition from the British society world to sunny Southern California has been much easier with her mother and sister by her side.

“I love [LA], I really love it, but it’s especially wonderful now because my mum and sister have come to visit. It’s so nice having them here,” she acknowledges. She confesses that life has been a little lonely lately, given that she’s been kicking around a 123-room home with no other company save for her husband and seven dogs (a Rottweiler, a Cavalier King Charles spaniel, a Pomeranian, a Boxer, a Bulldog and two Dobermans). Still, Petra is happy she made the move: she adores the sunny California sunshine, warm weather, outdoor activities like hiking at Runyon Canyon and dining at haute restaurants such as Giorgio Baldi, Boa and Madeo.

“The only part of London I miss are my family and friends,” Petra says, insisting that the change of location has been good for her— and that she’s beyond happy to have left her hometown behind.

“I don’t miss London the place, particularly, I just miss the people,” she continues. “LA people are really friendly, but I don’t think at this age you can make good friends. I grew up with my friends in London and I’m so close to my family; that’s the part I miss. I mean, I have social friends, but I don’t consider them good friends. They aren’t the people I grew up with.”

In a perfect world, she could convince her family members to leave London behind as well. “It’s so hard when they go back, but I’m trying!” she says. Her mother, as it happens, is about to fly back to the U.K. while 28-year-old Tamara has decided to stay in Tinseltown for a month. And why shouldn’t she? After all, she has her own bedroom, which Petra personally designed.“Everyone in my family has their own rooms. I decorated for them and did a good job, apparently,” she says proudly. “I know them so well. I know what they like.”

Her mother, a Croatian-born former Armani model, has been, in particular, an inspiration for Petra. “My mum always taught me not to just rely on the man in your life. She would say, ‘You never want to be the woman behind the man. You need to build something for yourself and not take a backseat to a person who is independent and powerful.’ That’s the best advice that my mum ever gave me, never to ask for anything or rely completely on anyone in life.”

She also turns to her famous father for advice as well, though moreso to impart career wisdom. “He always told me not to give up and to carry on. He’s always there if I need him,” she says of 81-year-old Bernie.

She continues: “He has such a strong work ethic, and so does my mum. They both came from nothing, and I think that’s what motivates me. He’s in his ‘80s and doesn’t need to work, quite clearly, but he chooses to. I have so much respect for that. He’s lucky because he loves what he does, just like I do working with Stark. We’re both in fortunate positions.”

But don’t confuse “fortunate” with “spoiled.” Petra is sick of all the misconceptions about her wealth and social status. She’s grateful for what she has and doesn’t take it for granted, but believes the constant and consistent harsh criticism she endures is unfair and unfounded.

“I just keep hearing ‘She’s spoiled’ and ‘She loves to shop and live off of her parents’ and it’s getting tedious and trying,” Petra says now. “Yes, I know I’m wealthy and privileged; I understand that. I know I’m fortunate and very lucky. But at the end of the day, I could choose to sit back and do nothing, watch TV all day or go out partying, but I choose to do something for myself instead. I’m working even though I don’t need to. If people want to stereotype me and say I don’t do anything, let them. I know it’s not the truth.”

Another thing that peeves Petra— who describes herself as “shy, hard-working loyal and funny”— is the misuse of her last name, as she is not, in fact, actually an Ecclestone anymore. Since marrying entrepreneur James last August, she has officially taken her husband’s name and become a Stunt. What’s more, she’s even renamed her home to reflect her new surname. “We call [The Manor] ‘Stunt Manor’ now,” she laughs, though her mood quickly becomes serious. “I changed my name from Petra Ecclestone to Petra Stunt; I took my husband’s name. It doesn’t bother [my husband] when people refer to me as an Ecclestone, but the fact remains that I changed it, so out of politeness people should call me by my real name. I’m traditional, and if I have children, I want them to have the same name as my husband. It’s not natural to me otherwise.”

Though she says she hopes to have children before the age of 30 (“but whatever happens happens”) and has big plans for the future that include a footwear line, opening her own LA boutique and even taking cooking classes to prepare her husband’s favorite dishes, right now she’s focusing on Stark and her work with the Starlight Children’s Foundation. She will, in fact, open her house to others for the first time ever in February of 2013 to host a party for the charity.

Though the future looks bright, right now Petra is content with her present. “I’m working on growing the business right now. I want to build something for myself,” she says before pausing to ruminate on the concept of empowerment. “Am I powerful? Well, I’m trying to get there,” she maintains. “I’m one step closer to it.” As for the flashy, attention-grabbing Barbielike car? Like most things in Petra’s life, the bright pink façade is just an optical illusion. “Having that car was my dream. I thought ‘Why not just do it?’ I don’t care what people say; I’ve always wanted a pink car. I feel like every girl needs that. But it’s just a wrap [a large graphic vinyl decal that can be easily removed]— the car is white. I could take it off if I wanted to.”

But she doesn’t want to, and that is the point. Living your life the way you want without caving to public opinion? Now that is power.